① after+一段時(shí)間表示“在……之后”,也可用“一段時(shí)間+later/after,多用于一般過(guò)去時(shí)中。
他們兩天后到達(dá)了山頂。
They reached the top of the mountain after two days.
They reached the top of the mountain two days later.
They reached the top of the mountain two days after.
② after+時(shí)間點(diǎn)可用于一般現(xiàn)在時(shí)、一般將來(lái)時(shí)或一般過(guò)去時(shí),表示“在……之后”。
She will arrive after five o'clock. 她將在5點(diǎn)鐘后到達(dá)。
It began to rain after ten last night. 昨晚10點(diǎn)鐘后開(kāi)始下雨。
He usually takes a walk after he gets up. 他通常起床后散步。
③ behind用作介詞或副詞,指位置,意為“在……后面”,還可引申表示“支持;落后”,也可指時(shí)間,意為“比……晚,晚了”。
She came out from behind the door. 她從門后出來(lái)。
They are fully behind the welfare policy. 他們都全力支持福利政策。
Our team is behind by two points. 我們隊(duì)落后兩分。
The clock is a little behind time. 這鐘稍微慢了一點(diǎn)。
He is a month behind with the rent. 他已拖了一個(gè)月沒(méi)交房租了。
④ in同表示一段時(shí)間的詞語(yǔ)連用,如:in three days,in 2008等。要注意的是,in引導(dǎo)的短語(yǔ)所在句中的謂語(yǔ)動(dòng)詞,如果是非延續(xù)性動(dòng)詞的一般將來(lái)時(shí)或過(guò)去將來(lái)時(shí),in表示“在……之后”,而如果句中謂語(yǔ)動(dòng)詞是延續(xù)性動(dòng)詞,in表示“在……之內(nèi)”,相當(dāng)于within。
He will arrive in 5 hours. 他將在5個(gè)小時(shí)后到達(dá)。(不是“5個(gè)小時(shí)內(nèi)”)
We shall go for a holiday in two weeks. 我們將在兩周后去度假。(不是“兩周內(nèi)”)
He said he would be back in an hour. 他說(shuō)他1個(gè)小時(shí)后回來(lái)。(be back為非延續(xù)性動(dòng)作)
I shall work here in two weeks. 兩周內(nèi)我將在這里工作。(work是延續(xù)性動(dòng)詞)
They built the bridge in six months. 他們?cè)?個(gè)月內(nèi)建造了那座橋。(=within)
She learnt to drive in three weeks. 她用3周時(shí)間學(xué)會(huì)了開(kāi)車。
=After three weeks she could drive.
after 指動(dòng)態(tài)的、次序的先后,而behind指位置的后面,表示靜態(tài)。